This seems like it is going to be a very fun game to play.
First of all, if you don't like SciFi settings, you probably won't have a lot of fun with the game (but that should be clear upfront from the title). Personally i love SciFi so i love it :D.
You should know that the story, and the idea of the game say: You land on an alien planet full of unknown dangers and lots of decisions to make. So don't expect huge wars against other civs too soon since there are huge crowds of aliens and miasma(-10hp per turn for units in the tile) to take care of!
It does everything right that annoyed me in Civ V(including Gods and Kings and some extra Civ dlcs):
-You can set up trade routes to "city states", other civs, or your own cities. You can also build explorers that examine fossils and old ruins. (It may have been in some Civ V dlc but here you get it for free.)
-When other leaders beg you for something you get a favor in return, instead of nothing. So you actually have a physical trading value!
-Diplomacy in general has improved: now you can see exactly why they like/dislike you.
-Instead of just sending a spy in a city you now have intrigue levels (1-5) and different actions for each of them. Reaching from stealing energy(the money in this game), science and technologies to luring siegeworms (a damn powerful alien) to the city! (Attention, because stealing tech sometimes gives you affinity levels!)
-You've got health now instead of happiness, giving bonuses to culture, science, etc. (if negative it's the opposite)
You have 3 affinities that change your appearance, gameplay and units:
Harmony (adapting to the new Planet), Purity (making a new earth), Supremacy(turning into cyborgs). Leaders of other affinities won't like you and will (depending on how far you differ in affinity) declare war on you.
some more new stuff:
-aliens are not barbarians, they defend their nests, if you get too close, and their strong friends will come and get you if you kill too many of them.So be careful!
-Satellites in the new orbital layer(for energy, unit bonuses, for crushing your enemies,...)
-a colony doesn't simply appear from nothing, it takes several turns for a colony to turn into a city
-if you conquer a city you it takes several turns to be usable, but it doesn't take a building.
-you get new units and upgrades by affinity (gained by technologies and quests).
-there is a huge replay value because you choose from different sponsors, with different positive effects, decide which cargo you take with you, and lots of things before you even start. the map is always randomly generated and for each building there is a quest, where you can choose from 2 bonusses so each game is completely different!
-Quests lead you to one of 5 posible endings( 3 of them for the affinities, domination and contact where you get contact with a developed alien race.
-Lots and lots of quests.
I hope i gave you a good overview,
so have fun!